The invention relates to a stick for a string instrument bow, comprising fiber-reinforced synthetic material and adapted for receiving a frog and for attaching hair thereto.
Furthermore, the invention relates to a method of manufacturing such a stick for a string instrument bow.
Usually, bow sticks, including the head, for bows of string instruments are made of fernambuco wood; these selected wood pieces must be stored and dried flawlessly for long periods of time, before the respective bow stick is made, at the making of which the distribution of weight, the position of the center of gravity and the resilience are important. To the bow stick, a tensioning device for bow hair called frog as well as the hair (i.e. the hair of the bow) are attached to complete the bow.
Lately, in view of the restrictions regarding the recovery of wood pieces for string instrument bows as well as of the time consuming and expensive preparation of bows from these wood pieces, suggestions for utilizing more recent manufacturing technologies have already been published wherein for the bow stick particularly fiber-reinforced synthetic material, such as carbon fiber materials, optionally using an internal stick core of a light-weight material, such as particularly balsa wood, should be employed, cf., e.g., WO 84/02792 and DE 40 14 894 A1. Even though at these known bow sticks an adaptation of e.g. the strength or sound propagation properties has been desired to a certain extent by the material selection, wherein also, other than with wooden sticks, a reproducibility should be ensured, it has nevertheless been attempted to achieve properties for the bow stick made of synthetic material as similar as possible to those of bow sticks made of wood. This also applies to the bow according to WO 92/09068 whose stick is substantially formed by a hollow synthetic material stick in which there is housed a tensioning element capable of being biased by a threaded screw. By this the bow can be biased in the interior of the stick in parallel to the tension caused by the hair, by which, however, necessarily also the curvature of the stick will change with the bias which, however, may be detrimental for playing when the hair is pressed onto the strings of the string instrument.
The idea forming the basis of the present invention is to provide a bow whose properties are different from those of conventional bows, which allows for new playing techniques, instead of imitating the conventional wooden bow or of attaining, with the new material, properties as similar to those of the former as possible. It must be taken into consideration that, as tests and measurements have shown, in conventional bows, usually the stiffness of the respective bow stick is to be chosen approximately proportional to the weight of the stick so that the quotient from weight and stiffness will remain approximately equal for bows (or, more exactly, bow sticks) of different weight.
In the tests which have led to the present invention, the deformation, i.e. deflection, according to the following conditions has been chosen as a measure for the stiffness of the bow sticks. The respective bow stick--still without hair and frog thereon--at its handle end is clamped at its outer side as well as at a distance of 130 mm therefrom at its inner side. A force corresponding to a weight load of 300 g is then exerted at the head end; accordingly, the bow stick is downwardly deflected or bent, and this deformation or deflection is measured and used as a measure for the stiffness of the bow stick.
For conventional violin bows and viola bows, there resulted the following values according to Table 1, and it is apparent that comparable product values (i.e. for bows of the same type) are always relatively close.
TABLE 1 ______________________________________ Weight of the Deflec- Deflection Stick tion .times. Weight [g] [mm] [mm.g] ______________________________________ Violin bow, light 33 42 1386 normal 39 35 1365 heavy 45 28 1260 Viola bow, light 40 33 1320 normal 43 30 1290 heavy 47 26 1222 ______________________________________
Similar results could be found for conventional violoncello bows as well as for double-bass bows, cf. Table 2.
TABLE 2 ______________________________________ Weight of Deflec- Deflection the Stick tion .times. Weight [g] [mm] [mm.g] ______________________________________ Violoncello bow, light 45 27 1215 normal 52 19 988 heavy 57 17 969 Double-bass bow, light 57 16.5 940.5 normal 65 14 910 heavy 85 10 850 ______________________________________
The test length of the individual bow sticks was a common stick length and was 70 cm for the violin bow, 69 cm for the viola bow, 66 cm for the violoncello bow and 64 cm for the double-bass bow.
From preceding Tables 1 and 2 it is apparent that the stick of known bows is the stiffer, the more massive the bow stick, a high stiffness of the bow being desired for many playing techniques, yet this should not be associated with a correspondingly high mass of the bow; the high mass, and the high weight of the bow, respectively, do mean a certain moment of inertia which is detrimental when changing the direction of stroke and in bouncing bow techniques. A light-weight bow in turn, however, is relatively flexible, i.e. it has a relatively pronounced deflection, and with a high bow pressure required for obtaining a higher sound volume, this deflection will lead to a contact of string, hair and bow stick and thus give rise to very unpleasant secondary noises.